The half-write test reports a session that closes under a question as a failure instead of ending test_dev

TODO.org

@@ -1789,12 +1789,6 @@ crashed session keeping its directory.
 The fork pool is drained before anything reads the failure count, and a nonzero
 count is an exit status. A red row used to be able to print and pass.
 
-** TODO test_dev dies on Wire.Closed after the half-write abort
-Intermittent, on an unmodified tree too: the =--llvm= half-write daemon in
-=test_dev.ml='s =half_written= sometimes exits before it replies to =abort=, and
-=request= raises =Wire.Closed= uncaught, so test_dev ends with a fatal, no =FAIL=
-line and every later row unrun.
-
 ** WAIT An x86 dev session's read of a dyn global after an allocating thunk failed once
 WAIT on a recurrence; the test now prints the failing read's own reply.
 The one failure's message came from a second read, which said "kept"; the failing

test/test_dev.ml

@@ -7034,6 +7034,9 @@ let () =
                                        :: _); _ } -> n
           | _ -> ""
         in
+        (* A daemon that goes away mid-question is a failure named here, not
+           a [Wire.Closed] that ends the binary with every later row unrun. *)
+        (try
         if not (await (fun () -> inside () = "in-local")) then
           fail "%s: the program never stopped inside the local's assignment" flag
         else begin
@@ -7072,7 +7075,10 @@ let () =
                   (String.concat ", "
                      (List.map (fun (n, ty, v) -> n ^ " " ^ ty ^ " = " ^ v) got))
           end
-        end;
+        end
+        with (Wire.Closed | Unix.Unix_error _) as e ->
+          fail "%s: the half-write session ended under a question: %s" flag
+            (Printexc.to_string e));
         (* No [close]: the program is stopped with nothing left to resume into,
            so the way out is the abort, and the daemon follows the program. An
            abort is refused by a program that is *running*, which is what a